Scientific and Useful

Western Star, Issue 840, 3 May 1884, Page 1 (Supplement)

Scientific and Useful

THE SUNSETS. Professor Langley, of the Allegheny Observatory, has been interviewed by a reporter about the sunsets, and has expressed the opinion that there is not only no antecedent improbabilty that the volcanic eruptions were the cause, but that they are the most likely cause we can assign. Professor 0. A. Young, of Princeton, says that the volcanic theory seems to him to be the true explanation. PURE AIE. Two scientific investigators—one Swiss and the other French —have been analysing the Alpine air. They ascertained that entirely pure air is not found until an altitude is reached of from 6000 to 13,000 feet above the level of the sea. The atmosphere round the lakes below that level, however pure and healthful apparently, was found to contain bacteria. Nevertheless, it was found pure enough by comparison with that of the French capital, where the bacteria contained in a square foot of air is 7000 times more numerous than those of the same quantity of air in one of the Swiss valleys. HEAT CONDUCTIVITY. The experiments of Peclet give the following as the conducting power per square foot of different materials, difference of temperature 1° Fahrenheit: — Copper, lin. thick, 515 heat units per hour; iron, lin. thick, 233 heat units per hour; ordinary plaster, lin. thick, 3'86 heat units per hours ; writing paper, lin. thick, 346 thousandths of a heat unit per hour; wool, any density, lin. thick, 323 thousandths of a heat unit per hour; blotting paper, lin. thick, 274 thousandths of a heat unit per hour. These figures show that copper conducts 1900 times as much heat as blotting paper, and 1600 times as much as wool, Iron conducts 850 times as much as blotting paper, and 721 times as much as wool. These expenments/Show blotting paper to be the best knovrn non-conductor of heat, with wool falling but a few degrees below. A NEW THEORY OF LUNAR FORMATION. Noticing the fact that there is a sequenc'e in size in groups of craters, I was led to believe that this represented a sequence in time also. Hence I was led on from the inadequate explanations at present in vogue to believe that the rings are made of condensed vapour, snow, of a sort not necessarily exactly as ours, and that the solid ejecta piled to form the cones in the plain (beyond which the ejected vapours fall), condensed as hail or snow, and circle, fountain wise, far beyond, being in a vacuum. Let us assume that the moon and earth are parts of one mass, and that the materials are not very dissimilar ; that when separated each had a far larger atmosphere in proportion than we have now, and that from the far higher temperature the water was more or less suspended as steam or cloud. Now, as time passed on, the moon cooled down to, through, and past the earth’s present state. Then a time would come when we should see our Polar and Arctic phenomena, absence of life, and general similarity to what we see on the highest terrestrial elevations. At this time we should have simply a deposit of solidified snow, showing angular formations in places and in others the reverse, where the snow can lie for ages unchanged under a vertical tropical sun. In the cab Himalaya it does so, the conditions necessary being bright above the snow line on a greatly attenuated vapour. We can further understand the gradual encroachment of the Arctic icefield till they meet and case the earth in ice, below which in the oceans there would still be enormous reservoirs of water at 32deg. The decreasing temperature would necessitate contraction of the globe, and the ice-shell would be ruptured, and large volumes of water emerge and flood the ice-crust, level it, and being repeated, it might gradually raise the level, and thus large raised flats may have been caused. Most of the lunar surface that we see is actually made of the lunar oceans, forced through a frozen solid surface, and deposited outside till there was no more water or vapour to. come out. The later ejections would only be able to melt a small cavity or crater hole, and pile the precipitated vapour close round. This would explain the otherwise difficult problem as to what becomes of the portions of the rings effaced. They are melted away, and thus also the smaller circles may at times be the deeper ones. While the oldest of these circles is at the snow-line, the second or smaller may have been formed below the snow line, but the deposit piled up to the snowline, and in the same way, as the cooling went on, the the third, the smallest and deepest, would be formed. In the case of large lunar rings, the vapour rises from either an orifice or off a water basin that surrounds one, and the vapour is deposited in a circle around. If there were winds on the moon, we should not see the deposit as a true ring, and if there was a steady and slow drift in an extremely rare atmosphere, we should see elliptical craters. The objection that snow would appear as dazzling white is met by the fact that meteoric dust falls on our Polar regions even in such quantity as to be visible to the eye. Our snow is renewed, but the lunar snow is permanent. The long lines of tiny craters would be due to the vapour rising through faults. The concentric formation in the walls of the large-walled craters is obviously a formation from a centre ; it shows a formation from a centre as surely as the earth’s Polar ice-caps show the from a circle to a centre. The size of the walled plains seems to preclude the formation of a ring from solid rock ejected. They would seem more like frozen precipitated vapour, deposited while the contained sea Was near and just below the line of perpetual ice.— 'H!. Peal, Assam.

M. CflEtßEltl. After a service of more than half a century as director of the Q-obelin’s Manufactory, this illustrious chemist has been placed on the retired list, and although in less than two years he will have completed 100 years of age, he considers that he has not been well treated. It would appear, however, that in order to spare the feelings of the old gentleman, he has been allowed to retain his appointment, with the salary attached. He is said to have never drank a glass of wine in bis Ufa*